Array modifier - edit base object
I speculate that the problem lays in a slight missunderstanding of the concepts of object/edit mode and modifiers. For better understanding maby you should update your question and add some visualization what you want to accomplish exactly and what is not working as expected. Then if you put a comment under this answer i could take another look at it and edit my answer accordingly.
the only way to realy edit the array itself in object mode is via the thwo separate array modifiers. Relative offset values or object offset can produce diffrent results. Transformations will apply to the whole object+array-setup.
the other way would be to edit your base mesh in edit mode. This edit will get passed down first to the one array modifier and then also this result will get passed down as a whole to the next array modifier. Individual edits are not possible, as for they are not what array modifier is intended.
There are other ways of working with seriality and transformation offsets in it, so it would really help knowig what you want to suggest other solutions. :)